This invention relates to fluid reclamation devices which are used with engines using lubricating oils and hydraulic systems to remove solid contaminates and water or other volatile contaminates from the lubricating oils or hydraulic fluids. More particularly, the invention relates to a unique evaporation plate and evaporator head and an improved filter assembly.
Oil reclamation devices of the general type disclosed and described herein are generally well known. These devices are used to remove both solid and liquid contaminates from the lubricating oil. It is well known that oil in and of itself does not "wear out". Once the solid and volatile contaminates are removed from the oil, the oil is substantially reconditioned and remains in a useful state.
A discussion of oil reclamation device is found in U.S. Department of Energy publication DOE/BC/1O256-1 Initial Assessment of Selected Advanced Lubricating Oil Filter, Sept. 1981. As part of the publication, patent and literature searches were conducted. Fifty seven patents were listed which showed filters that extract vapor from oil under vacuum and/or with added heat along with seventeen literature references.
Pertinent prior art which is specifically directed towards oil reclamation devices of the general construction of the present invention are typified by the "Engle" patents Nos. 4,289,583, 4,227,969 and 4,189,351 currently assigned to the assignee of the present invention.
U.S. Pat. No. 4,289,583 discloses an oil reclamation device with an evaporator head having a heat transmitting member mounted in a cavity in the evaporator head, an evaporator plate mounted to the evaporator head to form a baffled evaporator chamber and a filter container secured to the evaporator plate. The filter container is provided with an oil inlet valve at its bottom.
U.S. Pat. Nos. 4,227,969 and 4,189,351 disclose oil reclamation devices of a similar construction, both having a fixed filter and oil inlet positioned in the base of the filter which disburses oil upward into the filter material composition.
It is known in the art to utilize removable filters in connection with heated oil refining apparatus to remove liquid and solid contaminates from the oil used in internal combustion engines.
For example in U.S. Pat. No. 4,146,475 the fine filter and coarse filter which are used in the apparatus can be replaced by separating them from the concentric cylinder housing by unscrewing the concentric cylinder housing.
In U.S Pat. No. 4,585,924 a spin on diesel oil filter is used. The filter is constructed of conventional paper pleated construction with a base plate having a central threaded bore. The filter is screwed onto the lower threaded end of a nipple on an associated spacer which is in turn threaded at its top and screwed onto a second externally threaded nipple that is cast in and extends from the manifold.
In U.S. Pat. No. 4,369,110 the filter cartridge is provided with a perforated web having a central internal threaded opening which is screwed onto the outside of the end of a coaxial pipe which serves as an oil inlet and conduit. A needle member is screwed to the inside of the coaxial pipe and is jammed into the filter media providing a passageway for the oil into the filter cartridge.
The following patents also disclose the general state of the filter refining art: U.S. Pat. Nos. 4,388,185; 4,354,946; 4,349,438; 4,272,371; 4,261,838; 3,912,631 and 2,707,051.
Numerous disadvantages are associated with these known devices. For example, oil flows directly at a fairly high flow rate into a specific area of filter without dispersal throughout the filter container causing filter clogging and an increase in the micro size of the particles that are able to be filtered. Oil containing unvolitized contaminates will pass from the filter directly out of the oil outlet means of the container because it will not be included in any thin film traveling over the vaporizing surface on the upper side of the evaporator plate.
It is important that the oil passing across the vaporizing surface be maintained in as thin a film as possible to promote vaporization of the liquid contaminates. With other known filter refining devices, if the longitudinal axis is angularly disposed more than 5" from the vertical while installed, the oil will all flow to one side of the evaporator plate. Consequently, the effectiveness of the device will be virtually destroyed because of the depth of the oil from which the volatile contaminates can be volitilized.
None of the prior art devices are designed to effect the greatest efficiency of removing the contaminates and maintaining the operation of the device. Pressure build-up within the container causes shifting of the filter medium during operation. Inefficient transfer of heat from the heating surface to the thin film of oil is encountered because of spacing problems in the heater cavity and lack of heat conduction. Finally, the use of the known devices in marine conditions is questionable because of the open electrical connections.
Another object of the invention is to provide a removable filter cartridge in an oil reclamation device which results in a significantly controlled flow of oil being treated.
A further object of the invention is to expose substantially all of the oil to substantially uniform mechanical filtration and vaporization treatment.
A still further object of the invention is to provide an evaporator plate and evaporator head with a heat transmitting member having interacting portions which contribute to establish a uniformity in heating and fluid flow through the evaporation chamber.
It is still a further object of this invention to provide a filter assembly which will obviate problems associated with the disposition of fibrous material in the filter as it is provided in prior art oil reclamation devices.